Our process
How we diagnoseProof before recommendations.
This page exists because "trust us" is not an argument. Here is the exact diagnostic every technician runs, the instruments they use, what you receive at the end, and the criteria we apply before anyone says the word replacement.
Why this page exists
Most HVAC upsells are not lies. They are guesses.
A technician arrives, the system is old, it is not cooling, and replacement is the fastest answer for everyone except you. No measurements, no evidence, no comparison against the repair cost — just a number on a tablet and a hot house creating the pressure to say yes.
We are not going to claim we are more honest than everyone else in Fresno. Plenty of good companies work this valley. What we will do is show you the process in advance, so you can hold us to it — and hold anyone else to it too.
If a technician cannot tell you what they measured and show you what they found, they have not diagnosed anything. They have estimated.
The diagnostic, step by step
Seven steps, run in this order, on every service call. Nothing here is optional and nothing here is skipped because a system looks old.
1
We ask what it has been doing
Before touching anything: when it started, what changed, what it sounds like, whether anyone has worked on it recently. The history narrows the search faster than any instrument.
2
Airflow and static pressure first
We measure total external static pressure across the air handler and check filter and coil condition. A restricted system mimics almost every refrigerant fault there is, so this comes before gauges go on. It is also where Fresno attic heat does most of its damage.
ManometerStatic pressure probes
3
Temperature split across the coil
Return and supply air measured at the plenum, giving us the delta-T. On a 105° Fresno afternoon the expected split is different from what a national chart says, which is why a system that "isn't cooling" is sometimes performing exactly as designed.
Digital probe thermometers
4
Refrigerant charge by superheat and subcooling
Not gauge pressure alone. We calculate superheat on fixed-orifice systems and subcooling on TXV systems, against the manufacturer's target for the actual conditions. This is the step that separates a real diagnosis from "it's low, I'll top it off."
Digital manifoldClamp probes
5
Electrical draw and capacitance
Amp draw on the compressor, condenser fan and blower, each compared against the data plate rating. Capacitors read in microfarads against their rated value — a capacitor that looks perfect can be well out of spec and quietly destroying a compressor.
Clamp meterCapacitance meter
6
Safety and controls
Contactor condition, wiring and lug tightness, condensate drain and float switch, thermostat calibration and staging. On gas equipment this is also where combustion and heat exchanger inspection happens — documented, never assumed.
Combustion analyzerInspection camera
7
We show you what we found
Photos or video of the actual fault, the readings that identified it, and every option with a firm price attached. Then we stop talking and you decide. Nothing gets touched before you approve a number.
What you actually receive
A diagnosis you cannot see is just an opinion. Here is what leaves with you at the end of the visit.
Photos of the fault
The actual failed component in your actual system, not a stock image or a generic diagram.
The readings
Superheat, subcooling, static pressure, delta-T and amp draw — the numbers, plus what they should have been.
Every option, priced
Repair cost and replacement cost side by side when both are viable, so you are comparing rather than reacting.
A second opinion, free
Take our findings to another company. If we are right it costs you nothing to check. We do the same for their quotes.
How we decide repair or replace
Age is not a criterion. These are, and we walk through them with you rather than arriving at a conclusion on our own.
- Repair cost against system value. If the repair approaches a meaningful share of what a properly installed replacement costs, that is a real conversation. If it is a $200 capacitor on a working system, it is not.
- Condition of the sealed system. A compressor or coil failure is a different decision from a motor or a control board. We tell you which one you have.
- Refrigerant type and availability. Older refrigerants get expensive and eventually impractical. That affects the math, and we will show you how.
- Repair history. A third failure in two seasons means something different from a first failure in twelve years.
- Warranty status. Parts still under manufacturer coverage change the repair cost dramatically. We check before quoting, not after.
- The rest of the system. New equipment on collapsed ductwork underperforms and disappoints. Sometimes the honest answer is fix the ducts, not the box.
What we will not do
Commitments are only worth something when they cost you money to keep. These cost us money.
- Quote a replacement before diagnosing. No number gets written until the seven steps above are finished.
- Add refrigerant and call it a repair. Refrigerant is not consumed. If it is low, it leaked, and we will find the leak or tell you plainly that we could not.
- Condemn a heat exchanger without evidence. If we call one cracked, you see the camera footage or the combustion readings that prove it.
- Recommend replacement on age alone. A fifteen-year-old system that measures well gets repaired.
- Size a new system by matching the old tonnage. Replacements get a load calculation. Oversizing is the most common install error in this valley.
- Start work before you approve a price. Not one dollar of labor or parts happens on assumption.
- Use the heat as leverage. If it is 108° and you want a night to think it over, that is a reasonable thing to want.
The diagnostic fee
Why we charge for the diagnosis
A free estimate is not free. Somebody pays for the truck, the tech and the hour, and in that model it is whoever ends up buying a system — which is exactly the incentive we are trying to remove.
Charging a flat fee for the diagnosis means the technician gets paid for finding out what is wrong, not for selling you something. Approve the repair and the fee comes off the invoice.
What the fee covers
- The full seven-step diagnostic on your system
- Photos and readings documenting what we found
- Every option priced, with no obligation to take any of them
- Waived entirely when you approve the repair
Six questions worth asking any contractor
Including us. If a company cannot answer these on the spot, that tells you something useful before you sign anything.
-
"What did you measure, and what were the readings?"
A real diagnosis produces numbers. Vague answers usually mean the system was looked at, not tested.
-
"Can you show me the failed part?"
Photos, camera footage or the component itself. There is no reason this should be a difficult request.
-
"If you are recommending replacement, what would the repair cost?"
You cannot evaluate a replacement quote without the number it is being compared against.
-
"Is the permit and code verification included in the price?"
California requires a mechanical permit and independent field verification on most changeouts. A quote without them is not comparable to one with them.
-
"Did you run a load calculation, or match the old tonnage?"
Matching the old unit repeats whatever mistake was made the first time. Ask to see the calculation.
-
"What is the labor warranty, in writing?"
Equipment warranties come from the manufacturer. The labor warranty is the part the contractor actually stands behind.
Already have a quote?
Put someone else's recommendation through this process
If another company has told you the system needs replacing, we will run the full diagnostic ourselves and tell you honestly whether their call holds up. Sometimes it does and we say so. No charge either way.
What Fresno homeowners say
★★★★★
I realized something was wrong with my AC when I got home Tuesday afternoon and noticed it wasn't blowing cold air. I called them right away, and they were able to send a technician to my Fresno home that same evening. The repair only took about 45 minutes, and everything was back to normal once the work was done.
Debbie Kram · Google review
★★★★★
Wow! Just an amazing experience! Air conditioner went out and they were able to get it fixed the same day! Wonderful crew and extremely nice. Would definitely use again.
Paige Pender · Google review
★★★★★
I had a great experience with this AC service company! From the moment I called, they were professional, responsive, and knowledgeable. The technician arrived on time, diagnosed the issue quickly, and explained everything clearly.
Angelica Torres · Google review
Questions about our process
How long does the diagnostic take?
Usually under an hour for a straightforward cooling or heating fault. Intermittent problems and airflow issues take longer because they have to be reproduced before they can be measured, and we would rather spend the time than guess.
Do you run all seven steps even for an obvious problem?
Yes. An obvious failure is often a symptom of a second one — a dead capacitor caused by a dirty condenser, or a frozen coil caused by a duct restriction. Fixing only the visible part means you call us again in three weeks.
What if you cannot find the problem?
We tell you exactly that, show you what we ruled out and what it cost to rule out, and explain what the next step would involve. We will not invent a repair to justify the visit.
Can I watch while you work?
Please do. Ask questions while we are on the readings. Customers who understand their system make better decisions, and better decisions are the whole point of doing it this way.
Do I have to decide on the spot?
No. Take the findings, take the pricing, sleep on it or get another quote. If a company needs your decision before they leave the driveway, that urgency is for their benefit and not yours.
What happens after I approve a repair?
Most repairs are completed the same visit, because our trucks carry the common failure parts. If something has to be ordered we tell you the timeline up front rather than after. More on the AC diagnostic.
Put us through our own process
Book a diagnostic and hold us to every step on this page.
California Heating & AC Repair is operated by Craftline Renovations, Inc. · CSLB License #999179 · Licensed and insured.